1. Field of The Invention
The present invention relates to a shutter, and more particularly to a hinge member rotatably connecting plates to each other, the plates constituting a shutter panels.
2. Disclosure of The Invention
Japanese Publication No. 61-137792A, Utility model, discloses one example of a shutter panels having a configuration shown in FIG. 14 in which a plurality of plates are rotatably connected to one another by hinge members.
A shutter panel 10 in this example includes slats 18 and hinge members 2. The slats 18 each have a plate 1 and a cylindrical portion 17 which is integrally and continuously provided on the plate 1 along opposite end edges thereof on the side of its long side. The hinge members 2 each include holding portions 28 each turnably fitted over the cylindrical portion 17, and a reinforcing member 29 provided between the holding portions 28. The shutter panel 10 is slidably held by a pair of guide rails 4.
As shown in FIG. 14, each holding portion 28 of the hinge member 2 has a C-shaped section formed with a slit along its longitudinal direction such that the cylindrical portion 17 is rotatable and is prevented from being pulled out. As shown with broken lines in FIG. 14, the holding portion 28 is rotatably fitted over the cylindrical portion 17 in a range between opened end edges of the slit.
Since the shutter has such a configuration, if the shutter panel 10 is held by guide grooves 40 of the guide rails 4 having curved portions R and is allowed to slide as shown in FIG. 15, the shutter panel 10 is automatically bent along the curved portions R of the guide rails 4 and slides in the guide grooves 40. When the shutter panel 10 is not used, it can be wound around a cylindrical drum disposed above the guide rails 4 and can be accommodated compactly.
However, the shutter panel 10 can easily be bent and extended straightly along the guide rails 4 or a take-up drum. Therefore, there is a problem that when the shutter panel 10 slides, the plates 1 are unnecessarily pivoted and caught by the guide grooves 40, and the shutter can not be opened and closed smoothly.
Such a problem appears remarkably when the guide rails 4 have the curved portions R, and if the shutter panel is indiscriminately bent as shown in FIG. 12, the plates 1 or hinges 2 are caught by the guide grooves 40 of the curved portions R, and the shutter panel 10 can not slide in some cases.
In such a case, it is necessary to once pull the shutter panel 10 to its initial state to improve the indiscriminate bending thereof, and to allow the shutter panel 10 to slide in its normal direction again, and there is a problem that it is necessary to repeat the same operation many times until the shutter panel 10 passes through the curved portions R without being caught by the guide grooves 40.
An object of the present invention is to provide a shutter including: a shutter panel having a plurality of plates rotatably connected to one another by means of hinge members; and a pair of guide rails formed with guide grooves for slidably holding opposite end edges of the shutter panel, thereby smoothly opening and closing the shutter even if a curvature of each the guide rail is varied along a sliding direction of the shutter panel.
To achieve the above object, a shutter of the present invention has a feature that the hinge member can be bent only in a direction in which a curvature becomes greater than a portion of the guide groove having a minimum curvature.
The adjacent plates are selectively rotatably bent only in a direction in which the curvature of the guide groove becomes greater. Therefore, when the shutter panel is allowed to slide along the guide grooves, the plates are prevented from being rotatably bent in a direction in which the curvatures become smaller and prevented from being caught by the guide grooves. Thus, a minimum curvature portion of the guide rail and the curved portion of the shutter panel smoothly slide.
Since the present invention has the above configuration, the following specific effect is obtained.
The shutter panel slides smoothly in the minimum curvature portion and curved portion of each the guide rail. Therefore, the shutter is smoothly opened and closed even if the curvature of the guide rail is varied along the sliding direction of the shutter panel.
Other object, features, aspects and advantages of the invention will become more apparent from the following detailed description of embodiments with reference to the accompanying drawings and appended claims.